Answer:
-4.7 times 10⁴
Explanation:
Check what numbers match: 5.1 times 10⁸ - 9.8 times 10⁴
Subtract and get: -4.7 times 10⁴
Simply put, you subtract the 5.1 and 9.8 like normal and subtract the exponents from the 10⁸ and 10⁴ since they have the same base.
I hope this helps!